getMutable

getArray

Expert: if the bit-width of this reader matches one of
java's native types, returns the underlying array
(ie, byte[], short[], int[], long[]); else, returns
null. Note that when accessing the array you must
upgrade the type (bitwise AND with all ones), to
interpret the full value as unsigned. Ie,
bytes[idx]&0xFF, shorts[idx]&0xFFFF, etc.